The environmental effects of various fishing methods

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I have met a number of students around campus at California State University, Monterey Bay (CSUMB), who love to fish. Some fish by rod and reel angling, others with traps, and some even slide into a wetsuit and jump into the water with a spear. For these students, fishing isn’t just about the catch, it’s about getting out and experiencing the marine environment.

“For me, fishing is something that I do more for the act itself, not necessarily to get seafood,“ said Jeffrey Chen, an environmental studies student at CSUMB. “It’s about the challenge, and the sport.” And he is right, anyone who has tried to catch their own seafood knows that fishing can be a real struggle at times. Other students may have mixed feelings about killing for sport or for food.

Ana Gonzalez, who also majors in environmental studies, believes, “Consuming fish produces negative environmental impacts similar to the consumption of other animals.”

Whether or not you are for or against consuming seafood, there is a longstanding culture around seafood that is not likely to disappear any time soon. In fact, global consumption of seafood is expected to increase by 19 percent in the next seven years, according to the Food and Agriculture Organization of the United Nations.

If you enjoy the process of catching or eating seafood, before you go out on your next trip, it is important to recognize which fishing methods are environmentally friendly, and which are not. Below (and online) is a broad overview of various fishing methods, listed from greatest to least environmentally impactful. Many of our commercial fishing methods have room for improvement and there are people working on improvements to the way they catch fish.

Blast Fishing: Kills fish through shock from the blast of explosives. Explosives used for blast fishing are usually homemade various of homemade bombs and dynamite. The habitat damage caused by blast fishing is incredibly destructive and irreversible, which is why it is illegal in many areas around the world.

Cyanide Fishing: Have you ever gone to a fish store to buy a pet fish? There is a chance that the pet fish was captured using cyanide fishing. A sodium cyanide solution is mixed a squirt bottle and taken underwater to stun fish. Cyanide is a poison and it often kills the targeted fish along with other marine life, like coral reefs. Despite being illegal in many countries selling ornamental aquarium fish, cyanide fishing is still a common method of capture.

Netting: There are many different techniques of netting that all essentially rely on meshes made from threads to catch fish. Some common methods of netting are: cast nets, drift nets, ghost nets, gillnets, and trawl nets. Many people are familiar with the environmental impacts of netting; however, some methods are considered very sustainable. Cast nets are small enough to operate by one person and result in little to no by catch. Larger netting techniques like bottom trawling, which relies on heavy weights to keep the net on the seabed, result in a large amount of both habitat destruction and by catch. Netting methods are used for a variety of marine life including: clams, mussels, oysters, scallops, and all types of finfish. Bycatch from nets can affect non-targeted species including sharks, sea turtles, and marine mammals.

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Trapping: Traps are set out in the water and left for a period until the fisher returns to retrieve them and whatever may be inside. The traps keep the catch alive which keep it fresh. A common type of trap used in the Monterey Bay is the crab pot, but other forms of traps are fish wheels, and fish weirs. Depending on the type of trap, traps can be low in environmental impacts. Traps are most often used in the Monterey Bay for crabs and cod. Traps like crab pots use long ropes floated to the surface by a buoy which sometimes break or tangle with marine life.

Angling: Perhaps the most iconic method of fishing next to netting. Angling utilizes angled shapes, like a hook, to catch fish. Often the angles, or hooks, are used with lines and are disguised as bait that tempt fish to bite. Recreational fishers commonly angle by using a rod and reel with line and one angle per line. Commercial fishers are known to use longlining, which is an angling technique that uses several of long lines cast out behind a fishing vessel. These lines can have hundreds of hooks per line which can lead to issues of by-catch. Single hook angling can be done with relatively low environmental impact, however, bottoms snags and cut lines can remain in the ecosystem and result in ghost fishing. Ghost fishing is a term used to describe fishing gear that gets lost at sea and drifts about the ocean killing marine life. Species targeted by angling are virtually all medium to large sized finfish: salmon, tuna, cod, etc. Bycatch from ghost fishing affects non-targeted finfish, sharks, sea turtles, sea birds, and marine mammals.

Spearfishing: A personal favorite of mine, spearfishing, is the most target-oriented method of catching fish. The spearfisher needs to see the fish before they can shoot it and results in zero bycatch among experienced spearfishers. Since the spear is attached to the speargun by a shooting line, ghost fishing from spearfishing equipment is also not a concern. However, in the cold waters around Monterey Bay spearfishing can be very equipment intensive. At a minimum you would need a 7mm wetsuit fins, gloves, booties or fin socks, mask and snorkel, weight belt, weights, and a speargun, polespear, or Hawaiian sling. Due to the sustainability of spearfishing governmental oversight allows spearfishers extended seasons where they can fish year-round in California.

Hand-Gathering: Hand-gathering requires little to no equipment and is the oldest method of seafood sourcing, first observed among hominids at an archaeological site in France dating back to 300,000 years ago. It’s a little straight forward but, hand-gathering seafood is the act of gathering seafood by hand. If people aren’t bringing, and leaving behind their trash, then hand-gathering can be done with relatively low environmental impact. Mussels, clams, and in the past abalone, are common species gathered by hand. Bycatch is not a concern when gathering by hand.